This invention relates to a method and device for producing a body ply material for use in, for example, a carcass of a pneumatic radial tire.
A conventional device for producing a body ply material is shown in Japanese Examined Patent Publication No. 35-18602. This producing device involves winding back several filaments from reels by an extruder, arranging them in parallel with each other, passing the filaments in unvulcanized rubber within the extruder, and extruding them in a predetermined width by a dice to manufacture a ribbon. The ribbon is spirally wound on a drum of a large diameter, while lateral edges are bonded to each other to form a cylindrical wrapper. Then, the wrapper is cut in parallel with the axial line of the drum to manufacture a sheet having a large area. This sheet is peeled from the drum and temporarily stored, or transported to a cutting machine for cutting the sheet into a large number of body ply materials in a predetermined shape.
However, in the conventional producing device, after a large sheet is manufactured by the drum, the sheet is transported to a separate sheet cutting machine which cuts the sheet into a large number of pieces to produce body ply materials. Therefore, a ribbon winder having a large drum, and a sheet cutting machine are required, thereby giving rise to a problem that a large space is required not only for installing both machines, but also for storing sheets of large area.
Also, since continuous winding of ribbon and cutting of cylindrical wrapper are performed on the drum shaft of one cylinder at the same place, the sheet manufacturing efficiency is reduced to cause another problem that a manufacturing cost for the body ply materials cannot be reduced.
Since the work for manufacturing a wrapper with a ribbon and cutting the wrapper into a sheet, and the work for cutting the sheet peeled from the drum are performed in separation, the work efficiency is reduced, so that from this aspect, the reduction in cost cannot be accomplished for the body ply materials.
There is a problem that a sufficient bonding force cannot be ensured for adjacent lateral edges of a continuously wound ribbon.
In addition, after the wrapper is cut, the operator must forcedly peel the cut sheet from the drum, so that a problem arises in that the sheet peeling operation is troublesome.
Conventionally, tires have been produced through mass production pointing. For example, in regard to body ply materials, wide and long sheets are successively fabricated, cut into a large number of sheets of predetermined dimensions, and stored as body plies. The stored body ply materials are delivered to the next process. In other words, large shape sheets are fabricated, and cut into body plies for use in the manufacturing of tires.
Apparently, the foregoing mass production system seems to be capable of efficiently manufacturing tires. However, since the mass production system involves manufacturing large sized sheets, and cutting the sheets into tire parts, not only large scaled manufacturing devices and cutting device are required for the sheets, but also a space for storing sheets are required. For this reason, a vast space is required for the factory, and immense energy is also required for operating the factory. Therefore, even if the mass production is oriented, the production cost is increased as a result, thereby failing to benefit from the merit of the mass production. Particularly, when a tire part manufacturing factory is separated from a tire forming factory due to restrictions on geographical conditions, a cost for storing and transporting tire parts accounts for a large proportion of a total cost, so that a reduction in the cost is extremely difficult. Further, since the storage of tire parts, and a transport process intervene between working processes, a variety of difficulties are involved in the quality management for the humidity, curing of sheet surfaces, prevention of dust adherence, and so on, thereby giving rise to a problem of a reduced yield of tire products.
This invention has been made in view of the problems inherent in the prior art as described. Its main object is to provide a method and device for producing a body ply material which is capable of significantly reducing a space for installing the body ply material producing device, and of eliminating a space for storing intermediates of the body ply materials.
It is another object of this invention to provide a method and device for producing a body ply material which is capable of reducing a producing cost, in addition to achieving the main object.
It is another object of this invention to provide a method and device for producing a body ply material which is capable of increasing a bonding force of adjacent lateral edges of a ribbon which is successively wound.
It is another object of this invention to provide a device for producing a body ply material which is capable of smoothly peeling a cut body ply material from the outer periphery of a drum, in addition to achieving the main object.